Sophism is an early Pre-Socratic school of philosophy in ancient Greece. It is the name often given to the so-called Seven Sages of 7th and 6th Century B.C. Greece (see below), but also to many other early Greek philosophers who were more concerned with Man himself and how he should behave than with big questions about the Universe. Rather than a well-defined school or movement, however, it is more of a loose grouping of like-minded individuals.

The term "sophism" comes from the Greek "sophos" or "sophia" (meaning "wise" or "wisdom"), and originally referred to any expertise in a specific domain of knowledge or craft. After a period where it mainly referred to poets, the word came to describe general wisdom and, especially, wisdom about human affairs. Over time, it came to denote a class of itinerant intellectuals who taught courses in "excellence" or "virtue", (often charging high fees for it), who speculated about the nature of language and culture, and who employed rhetoric to achieve their purposes (which was generally to persuade or convince others).

Sophists held relativistic views on cognition and knowledge (that there is no absolute truth, or that two points of view can be acceptable at the same time), skeptical views on truth and morality, and their philosophy often contained criticisms of religion, law and ethics. Many Sophists were just as religious as most of their contemporaries, but some held atheistic or agnostic views. Typical Sophist quotations include "Man is the measure of all things" (Protagoras) and "Justice is nothing other than the advantage of the stronger" (Thrasymachus, c. 459 - 400 B.C.).

Sophists had considerable influence in their time, and were largely well-regarded. They were generally itinerant teachers who accepted fees in return for instruction in oratory and rhetoric, and they emphasized the practical application of rhetoric toward civic and political life. Their cultural and psychological contributions played an important role in the growth of democracy in Athens, not least through their rhetorical teaching, their adoption of Relativism and their liberal and pluralistic acceptance of other viewpoints. Sophists were also some of the world's first lawyers, making full use of their highly-developed argumentation skill.

The early Sophists claimed that they could find the answers to all questions, which, along with their practice of taking fees and their questioning of the existence and roles of traditional deities, led to popular resentment against Sophist practitioners, ideas and writings. Some writers have included Socrates as a Sophist, although he was scrupulous in accepting no fees and making no claims of superior wisdom, and his most illustrious student, Plato, depicts Socrates as refuting the Sophists in several of his "Dialogues".

It is Plato who is largely responsible for the modern view of the Sophist as a greedy and power-seeking instructor who uses rhetorical sleight-of-hand and ambiguities of language in order to deceive, or to support fallacious reasoning. Plato was especially dismissive of Gorgias, one of the most famous and successful of the early Sophists. Sophism was thought capable of perverting the truth because it emphasized practical rhetoric rather than virtue, and taught students to argue any side of an issue. In most cases, our knowledge of Sophist thought comes down to us from fragmentary quotations that lack context, many of these from Aristotle, who, like his teacher Plato, held the Sophists in slight regard.

Owing largely to the influence of Plato and Aristotle, philosophy came to be regarded as distinct from Sophism, which was gradually became synonymous with the practical discipline of rhetoric, so that, by the time of the Roman Empire, a Sophist was simply a teacher of rhetoric or a popular public speaker. Indeed, for a time, Sophists started to suffer persecution, threats and even assassination. In its largely derogatory modern usage, "sophism" (or "sophistry") has come to mean a confusing or illogical argument used to deceive someone, or merely philosophy or argument for its own sake, empty of real content or value.

The Seven Sages of ancient Greece were seven wise men (philosophers, statesmen and law-givers):